Various surveys examined the patterns of e-cigarette use incorporating the causes for initiating or maintaining use and the prospects for e-cigarettes to service smoking termination.
Exporting data frequently includes a destined or indirect claim that using e-cigarettes will assist smokers in halting or decreasing cigarette use. Hold-up data, however, are quite restricted. Numerous studies have established temporary depletion in cigarette smoking while using and buying e-cigarettes.
Studies evaluated the following observed physiologic consequences related to severe vulnerability to e-cigarettes or e-cigarette aerosols:
- Vocal cord and throat irritation and dry cough at initial use, though complaints decreased with continuing use
- No change in heart rate, carbon monoxide (CO) level, or plasma nicotine level
- Decrease in fractional exhaled nitric oxide (FeNO) and increase in respiratory impedance and respiratory flow resistance similar to cigarette use
- No change in complete blood count (CBC) indices
- No change in lung function
- No change in cardiac function as measured with echocardiogram
- No increase in inflammatory markers
Exposure risks for non-users
Five studies addressed exposure risks for non-users. E-cigarette refill cartridges may contain toxic amounts of nicotine. Nicotine from the aerosol or the liquid can remain on surfaces for weeks to months and may react with ambient nitrous acid to produce TSNAs, leading to inhalation, ingestion, or dermal exposure to carcinogens. The primary indoor sources of ambient nitrous acid are gas appliances. Children are at risk of toxicity from refill cartridges; the flavourings may increase appeal while the total nicotine content is potentially life-threatening. The cytotoxic effects of refill solution components may be more pronounced on embryonic cells. Aerosol from e-cigarettes is only released during exhalation and content will vary depending on the users’ technique or other conditions, such as temperature.
Although e-cigarettes have potential advantages over traditional cigarettes, there are many deficiencies in the available data. Differences in product engineering, components, and potential toxicities make it difficult to discuss e-cigarettes as a single device. E-cigarettes may be useful in facilitating smoking cessation, but definitive data are lacking. E-cigarettes may provide a less harmful source of nicotine than traditional cigarettes, but evidence of decreased harm with long-term use is not available. It is encouraging that few serious adverse events have been reported related to e-cigarette use during the years the products have been available, but without a specific reporting mechanism, adverse event data may not be comprehensive.